CN1012328B - Rigid polymeric substance capable of being employed as magnetic recording medium and the magnetic disk produced from this substrate - Google Patents

Abstract

The present invention relates to a stiff polymer substrate for use as a magnetic-registration carrier, and magnetic disc obtained from this substrate. The substrate characterized by the following points : the said polymer is a thermotropic polymer and an inherent viscosity of at least 1 dlg-1. The preparation of the substrate consisting in performing an injection-moulding operation on the thermotropic polymer in a suitable mould fitted with a central injection system for the polymeric material, the temperature of the walls of the said mould lying in the range from 100 degrees C to 200 degrees C, the temperature of the injected molten polymer lying in the range from 280 degrees C to 350 degrees C, the injection time lying in the range from 2 to 10 seconds, the injection pressure lying in the range from 80 to 160 MPa and the holding pressure after injection lying in the range from 40 to 120 MPa. The substrate and the magnetic recording disc have the excellent surface quality and very good dimensionally stability and very low inertial moment.

Description

Rigid polymeric substance capable of being employed as magnetic recording medium and the magnetic disk produced from this substrate

The present invention relates to can be used as the rigid polymer matrix that the thermic that carries the magnetic recording body becomes polymer-matrix, also relate to the recording disc of making by this matrix.

As technical well-known, recording disc by one thin (thickness is about 1～2 millimeter) smooth disc rigid matrix constitute, generally there is a coaxial aperture center at this matrix, to link to each other with drive unit with suitable fixing, and (for example at least one face of matrix, applied the very thin suitable magnetosphere of one deck, coating thickness is 0.3～0.5 micron when applying the magnetosphere of magnetic paint base, and coating thickness is 0.05～0.2 micron when applying the disk of thin metal layer).

One or more read-write heads are housed on the magnetic coat in the known manner, make disk when rotation (rotational speed is about 3600 rev/mins) these magnetic heads on magnetic disk surface about 0.2～0.6 micron locate " hover ".

For the complete stability of the relative position that guarantees magnetic head and disk, must satisfy ask for something as the matrix of the ingredient of disk, be mainly:

Good rigidly (especially being reflected on the high elastic modulus) is to avoid warping phenomenon occurring under stress;

Surface quality fabulous (especially being reflected on the low roughness).

The dimensional stability under temperature or the temperature action good (especially being reflected on the very low this point of radial thermal expansion coefficient);

Moment of inertia little (especially being reflected on the very low this point of relative density); And

Chemical behavior and thermal behavior good (especially being reflected on the high this point of deformation temperature (being called for short DTUL) under the load), so that matrix on the one hand effect of the used solvent of the magnetic grain dispersion liquid of ability deposition or solvent mixture when carrying out magnetic coat electroless copper deposition operation (if with magnetic paint base magnetosphere), the high temperature of (if with magnetic paint base magnetosphere) when on the other hand during the ability deposition (if with the metal level that approaches) or bonding agent are crosslinked.

Aluminium alloy for example contains 96%(weight) aluminium and 4%(weight) the AA5086 type alloy of magnesium, can satisfy these different requirements preferably.But this class material is carried out machining and polishes is expensive.And oxidable rich iron intermetallics is arranged in these materials usually, form a lot of 2～10 microns lines of segragation, and these lines of segragation or in the process of machining and polishing or when aging the performance different.

Glass also is a kind of material that can be used as recording disc magnetosphere matrix preferably.But it can bring following shortcoming under many circumstances: at first, glass is crisp; Fragility means usually in material science does not have plasticity, can destroy suddenly when being hit; And glass is processed and polished is expensive; At last, it is good inadequately with the adhesion that will apply the magnetosphere on it.

Because the price of aluminum substrate is shared ratio height (being about 30%) in the total cost of making hard disc; and must be again when making the disk of thin magnetosphere with lumarith (for example electrolytic nickel sediment) protecting group surface from and improved cost; but also since with the associated many shortcomings of glass, therefore other is more suitable in the material of making the rigid magnetic disks matrix to need research.Along with occurring having the novel thermoplastic polymkeric substance of a lot of advantageous properties and adopt injection moulding in the seehears field, people have considered to replace aluminium and glass with suitable polymers.These materials are generally all inexpensive, and very light thereby moment of inertia is also little.But it is quite difficult making the disc matrix of being made by these polymeric materials have following desired combination property, and these performance requirements are:

The radial elastic modulus height preferably substantially exceeds the 5000Mpa(MPa) (pressing French Standard NFT51034) 50%EH and 25 ℃ of following mensuration;

The radial thermal expansion coefficient is little, its value be equivalent to or even be lower than the thermal expansivity (being about 30 microns/meter/℃) of aluminium;

The DTUL height is at least 150 ℃, for example so as to apply that disk behind the magnetosphere is easy to by heating furnace so that in the magnetisable material of deposition contained bonding agent crosslinked;

Shrink very for a short time during the demoulding, preferably do not shrink;

Making good use of of chemically-resistant product, used solvent when for example polymeric matrix wants anti-preparation to contain the dispersion liquid of the magnetisable material that will deposit; And

Can not change, otherwise humidity can make size change because of the influence that is resembled the Atmospheric components of humidity and so under the service condition, its intensity of variation corresponding to or surpass the caused variation of temperature difference.

Should be understood that, do not make raw material if when injection moulding, do not note adopting the polymkeric substance that has a good flowability in molten condition, so still can meet difficulty, the difficulty that product ran into of thickness can cause internal stress, make the matrix that obtains at last produce surface imperfection, occur thin-walled injection moulding the thickness product intrinsic warping phenomenon.

The polymeric matrix that can adopt is made (referring to periodical Plasfics Technology, Apr.1985, P73 etc.) with following material at present;

Polyimide is the product of Ultem1000 as the registered trademark of selling on the market.But this polymkeric substance poor rigidity, elastic modulus is about 3000 MPas, and the radial thermal expansion coefficient is big, is about 56 microns/meter/℃, so it can not be compatible with all existing trackers that are used for the aluminum substrate hard disc; With

Polycarbonate or acrylate copolymer (also referring to JA-A59/231,750), but the serviceability temperature of these two kinds of materials is very limited.

The rigidity recording disc matrix that the polymkeric substance that one of fundamental purpose of the present invention will provide a kind of usefulness to have following performance is exactly made;

Be easy to make with injection moulding;

Can make the matrix of gained have the advantage of plastics, particularly surface quality is very good, and is light, low cost of manufacture;

At least poor rigidity and thermal expansivity these two shortcomings have greatly been overcome.

Adding filler is a kind of known method that can improve plastics rigidity (if rigidity is too poor) and reduction plastic hot expansion coefficient (if thermal expansivity is very big).But when molding rigidity plastics matrix, must avoid adding filler, after adding filler, the surface quality of matrix is suffered damage.

In addition, thermoplastics is carried out single shaft or biaxial stretch-formed its elastic modulus of making improves, but these methods are not suitable for and must satisfy the disc rigid matrix that smoothness and thickness evenly require.

The present invention has utilized a kind of known polymeric material, this material is used to make the advantage of hard recording disc matrix, also nobody carried out research in the past, this polymeric material has special proper property, this performance can combine well unexpectedly with the effect of conversion condition, so that produce the characteristic of above-mentioned requirements.

Or rather, first theme of the present invention relates to and a kind ofly is used for the thin of recording disc with what polymeric material was made, smooth disc rigid matrix, and this matrix has following characteristics:

This polymkeric substance belongs to thermic and becomes polymkeric substance, and its flow temperature is 200 ℃～350 ℃, and logarithmic viscosity number is at least 1dlg ^-1;

In this matrix preparation process, be subjected to the molecular orientation of high degree, invite the preparation method thermic to be become polymkeric substance be equipped with in the mould that is applicable to polymeric material of central injecting systems one and carry out injection moulding, the die wall temperature is 100 ℃～200 ℃, the temperature of the molten polymer of being injected is 280 ℃～350 ℃, and be 2～10 seconds inject time.Injection pressure is 80～160 MPas, and keep-uping pressure after the injection is 40～120 MPas;

The relative density of the matrix that this molding gets is less than 1.8, and radial elastic modulus is 9000～18000 MPas, and the radial thermal expansion coefficient is 10～20 microns/meter/℃, and the deformation temperature under the load is at least 150 ℃.

Molecular orientation naturally and understandably takes place, and owing to the central feeding at product, this orientation is favourable and is that the plane is isotropic under the situation of circle symmetric geometry, can produce the structure with desired performance under conversion condition.

Generally, the key dimension of the disc matrix of the molding of gained is as follows: external diameter is 70～360 millimeters; Thickness is 1～2 millimeter.Generally, the most interesting form with the most use is: diameter is the matrix of 90 millimeters (31/2 inches) and 130 millimeters (51/4 inches), can make the disk that memory capacity is 5～16 megabits; Diameter is the matrix of 200 millimeters (8 inches), and to be used to make memory capacity be 10～50 megabits, have the used disk of microcomputer of several fixed disk stackers; Diameter is the matrix of 355 millimeters (14 inches), is used for the very high fixed disk unit of memory capacity.

Be suitable for realizing that thermic of the present invention becomes polymkeric substance and comprises full-aromatic polyester, alkyl aromatic polyester, full-aromatic polyester acid amides; Alkyl aromatic polyesteramide, poly aromatic azomethine, aromatic carbonate polyester and these mixture of polymers.

According to of the present invention one comparatively desirable embodiment, it is full-aromatic polyester that the thermic that adopt becomes polymkeric substance, alkyl aromatic polyester, aromatic carbonate polyester and these mixture of polymers.

Thermic becomes the poly-acid of full aromatics of (can generate anisotropic melt), such as United States Patent (USP) 3991013,3991014,4066,620,4075262,4118372,4130545,4181792,4188476,4219461,4224433,4230817 and 4346208 and the european patent application 86/420013.4(number of delivering be 0191705) description all arranged.

Thermotropic alkyl aromatic polyester is such as United States Patent (USP) 3778410,3804805, description all arranged in 428995,4311824 and 4355133.

Thermotropic carbonic ester polyester all has description in such as United States Patent (USP) 4107143,4284757 and 4371660.

Realize that it is above-mentioned general or more desirable that part of polymkeric substance that the selected thermic of the present invention becomes polymkeric substance, its flow temperature is 200 ℃～350 ℃, and logarithmic viscosity number is at least 1dlg ^-1, be 1.1～4.0dlg or rather ^-1" flow temperature " is meant that the edge of the sample that polymer flake or cut staple are such begins to become the temperature of bowlder; This temperature is observed sample with a microscope that the objective table (trade mark is Thermopan) of heating is housed and is measured by sample being placed on the glass cover-plate under the condition of the heating rate about 10 ℃～20 ℃/minute.Logarithmic viscosity number is with per 100 cubic centimetres of parachlorphenol and 1, and the solution that contains 0.5 gram polymkeric substance in the mixed solvent of 2-ethylene dichloride (50/50 volume ratio) is measured down at 25 ℃.

Being particularly useful for realizing that full aromatics thermic of the present invention becomes polyester, is those described in european patent application the 86/420th, No. 013.4 (number of delivering is 0191705).These polyester have following feature:

The repetitive that contains formula (I) also can contain formula (II), (III) and (IV) (IV) when needing:

(I) expression-O-

The structure of-O-, R in the formula ₁Represent methylidene or ethyl or chlorine or bromine atom, the R in each unit (I) ₁Can be same to each other or different to each other,

(II) expression-OC- The structure of-CO-,

(III) expression-OC-

-O-

The structure of-CO-;

(IV) expression-O

The structure of-CO-knot;

Unit (I) is 0.95～1.05 with the mol ratio of unit (II)+(III) sum;

In the potpourri of unit (II)+(III), unit (II) accounts for 0～70 mole percentage, and unit (III) accounts for 100～30 mole percentages.

The amount of unit (IV) is 10～300 mole percentages of the amount of unit (I).

These full-aromatic polyesters that particularly are suitable for also comprise the polymkeric substance of the aromatic units of those ester groups that can contain structure in addition and be different from unit (I), (II), (III) and (IV) (dioxy base unit and (or) dicarbapentaborane unit and (or) oxygen base carbonyl unit potpourri) generation.The total amount of the unit that these add in addition is no more than the 10 heavy mole percentages of unit (I).The example of the unit that these add in addition has:

(or)-O-

-O-(I ')

(or)

(I ")

R wherein ₂And R ₃Definition and top R ₁Definition identical, R ₂And R ₃Can be identical or different, thus make each unit (I ") can be same to each other or different to each other,

(or)-OC-

(II ')

(or)-O- (IV ')

Especially the alkyl aromatic thermic change polyester that is suitable for is in United States Patent (USP) the 4248995th and 4,311, those polyester described in No. 824, and it is made of some following unit:

X wherein ₁Expression by a first or ethyl or chlorine atom or bromine atoms replace 1, the 4-phenylene,

X ₂Be unsubstituted 1, the 4-phenylene,

X ₃Expression by two methyl or ethyl or two chlorine atoms or bromine atoms replace 1, the 4-phenylene, or 4,4 '-diphenylene or P, P '-diphenylene, wherein each benzene nucleus can be replaced by a methyl or ethyl or chlorine atom or bromine atoms

0.4≤a≤1 wherein

0≤b≤0.6

0≤c≤0.1

a+b+c＝1

Y represents 1.4-phenylene or 1.4-cyclohexylidene, or one contain two and can (can contain 8 carbon atoms by a singly-bound or acrylic acid chain, also can contain 1～2 heteroatoms when needing) group of continuous phenylene, an or divalence aromatic radical that contains two condensation benzene nucleus (key that wherein is connected on the carbonyl is relative and parallel) at least

Z represents-(CH ₂) _n-Ji 3≤n≤10

The mol ratio of Z/Y+Z is 20～50%

Especially the thermic change carbonic ester polyester that is suitable for is a United States Patent (USP) the 4th, 284, those described in No. 757.Those polyester are by forming with lower unit:

（Ⅸ）

R wherein ₄Base all is identical, each R ₄Expression by a methyl or ethyl or chlorine atom or bromine atoms replace 1, the 4-phenylene,

Each R ₅Basis representation one is unsubstituted 1, the 4-phenylene,

0.3≤a ' in the formula≤1; 0≤b '≤0.7; A '+b '=1.

R ₆Base can be identical or different, each R ₆Basis representation is selected order 1,4-phenylene, 1, and 4-cyclohexylidene, 4,4 '-biphenylene, 2,6-naphthylene, 4,4 '-the ethylene Oxy-1,1 '-biphenylene, 4,4 '-butylidene two Oxy-1s, 1 '-biphenylene and 4,4 '-hexylidene two Oxy-1s, 1 '-a kind of base in the biphenylene; The amount of unit (IX) accounts for 30～90 mole percentages in the potpourri of (IX) and (X); Unit (VIII) is 0.95～1.05 with the ratio of unit (IX)+(X) sum.

Thin disc rigid matrix of the present invention is made with injection moulding, and injection moulding is to carry out in the anisotropy district of the thermic change polymkeric substance that is adopted.Should be pointed out that anisotropy is easy to prove, when observing the polymkeric substance of molten state,, the birefringence and the reflection of polarized light can take place by crossed polarizers for the anisotropy sample with the optical system (90 ℃) that two crossed polarizers are housed.The anisotropy of polyester of the present invention is to prove with the hot optical means of French Patent (FRP) 2,270,282 described TOT.Should be understood that " each to incorgruous district " is meant such temperature range, the temperature during from the birefringence that begins to take place light by two crossed polarizers and transmission is to suitable high temperature; The upper limit of this temperature range is variable, but the polymkeric substance of fusion has anisotropy and the danger that do not have to decompose under ceiling temperature.Generally, the temperature range in the anisotropy district of the anisotropy melt substance of the interior injection moulding of the scope of the invention is at least above 30 ℃.

Or rather, the manufacturing of matrix of the present invention is with existing equipment the anisotropy melt substance to be expelled in the disc mould, the geometrical property of mould adapts to the desired size of matrix that will make, a central injecting systems is housed so that polymeric material is injected on the mould.Following principal character can be used as the example of die size: external diameter is 77～360 millimeters, and thickness is 1～2 millimeter.The operating conditions that can make matrix of the present invention as mentioned above, promptly the die wall temperature is 100 ℃～200 ℃; The temperature of molten polymer is 280 ℃～350 ℃; Be 2～10 seconds inject time; Injection pressure is 80～160 MPas; Keep-uping pressure is 40～120 MPas.

The relative density of the disc matrix that molding gets is very low, less than 1.8, and has desired combination property.Or rather, its radial elastic modulus is 9,000～18,000 MPa, and the radial thermal expansion coefficient is 10～20 microns/meter/℃ as previously mentioned less than 30 microns/meter ℃.The advantage of the matrix that this molding gets is not limited to this two kinds of performances; The DTUL that should be pointed out that these materials especially is very high, is at least 150 ℃, can be high to 240 ℃ even higher, and shrink during demoulding for a short time, dimensional stability is good, with regard to its physical and chemical performance, is insensitive naturally to solvent, is very sensitive to humidity.In addition, the feature of the used anisotropic melt of injection moulding is that flowability is fine when being heated, and so just can be made into the goods with fabulous surface profile; Or rather, the matrix that molding gets is perfectly smooth (surfaceness is less than 0.05 micron), and thickness evenness is fabulous.

After molding process is finished, can before the demoulding or after the demoulding matrix of gained at high temperature be heat-treated, but this temperature to be lower than the fusing point of polymkeric substance.After the demoulding and the cooling, the matrix that makes is generally handled with processing (or last finishing) medium pore, on its at least one face, after surface degreasing, applied magnetosphere then.

Therefore second theme of the present invention also relates to the recording disc of gained after applying magnetosphere on the matrix that above-mentioned molding gets.

Or rather, the present invention also relates to such recording disc, this disk comprises a thin smooth disc-shaped rigid polymer matrix and is deposited on granular pattern or thin layer type magnetic coat at least one face of matrix, is characterized in that described matrix will meet the given definition of this instructions in the above.

Because the chemical-resistant reagent and the temperature tolerance of matrix of the present invention are all fine, therefore can adopt all method deposition magnetospheres.

When particularly adopting the granular pattern magnetosphere of magnetic paint base, can adopt the unit painting method that is called " spinner " or centrifugal coating, this method is sprayed on the level of being fixed on by a nozzle with magnetic coating or is vertically mounted on and makes on the matrix on the rotating disk above magnetic coating is deposited on.Magnetosphere generally comprises magnetic, and magnetic can be iron oxide (Y-Fe ₂O ₃, also can add Fe when needing ₃O ₄), also can add cobalt when needing, add passivated iron, interpolation-nitrogenize two iron or add six barium ferrites, these additives are dispersed in the potpourri of a suitable solvent or this solvent, and magnetosphere also contains suitable bonding.In addition, magnetosphere also can contain lubricant as Winchester type method commonly used.After coating and drying, the matrix that has applied magnetosphere is heat-treated so that bonding agent is crosslinked, can under about 200 ℃, heat-treat during for example with epoxy resin as adhesive.But the character that depends on bonding agent also can adopt other cross-linking method, for example carries out irradiation treatment or electron beam treatment.Make the disk of gained carry out conventional polishing and cleaning after crosslinked.The thickness of magnetic paint base sedimentary deposit is decided on the purposes of disk, is generally 0.3～5 micron.Should be pointed out that disk can coat very thin one deck lubricating layer before use.

When obtaining thin layer type magnetosphere adoptable other depositing operation be by or cathodic sputtering make the composition thermal evaporation of cobalt cobalt, chromium, nickel or its alloy; also can then deposit when for this method, needing one deck lumarith and (or) protective seam (for example, using aluminium oxide) or lubricating layer (for example using carbon).The metal layer thickness of deposition is decided on the purposes of disk, is generally 0.05～0.2 micron.

Also have a kind of alternative technology in addition, promptly carry out the deposition of magnetosphere, but matrix must metallize in advance by electrolytic process.

Should be pointed out that the disk that makes has the excellent comprehensive performances of matrix above-mentioned, particularly surface quality (roughness, smoothness), rigidity (elastic modulus), dimensional stability (thermal expansivity) and thermotolerance (DTUL) are all fine.

The following examples are used for illustrating the present invention, and the present invention never is limited to these.

Embodiment 1

The embodiment for preparing thin disc rigid matrix of the present invention.

1. used thermic becomes the explanation of polymkeric substance

Prepared european patent application 86/420, the 013.4(number of delivering 0191705) described in the full-aromatic polyester of type.

Following reactant and catalyzer are packed in the poly-reactor of-7.5 reductions, and reactor can stir and utilize round-robin heat-transfer fluid heating in reactor jacket, and distilling apparatus is housed and with the device of inert gas purge:

(1) diacetic acid chlorohydroquinone ester: 1028 grams

(mol ratio (1)/(2)+(3)=1)

(2) terephthalic acids: 373 grams

(in the potpourri of (2)+(3), accounting for 50 mole percentages)

(3) two (4-carboxy phenyl) ether: 581 grams

(in the potpourri of (2)+(3), accounting for 50 mole percentages)

(4) right-acetoxy-benzoic acid: 275.5 grams

(34 mole percentages of (1))

(5) magnesium acetate: 1.13 grams

〔500PPm〕

The reactor nitrogen purge is then with 260 ℃ of heat-transfer fluid heating 2 hours 20 minutes.The volume of the acetate that distills is 506 cubic centimetres (are theoretical value 83%).Be increased to 330 ℃ gradually with 40 fens clock time temperature that metal is molten then, pressure is then by 1,010 * 10 simultaneously ²Handkerchief reduces to 0.39 * 10 ²Handkerchief.After the acetate distillation stops, continuing to keep 330 ℃ of temperature and 0.39 * 10 ¹²Handkerchief pressure reaches 12 minutes 30 seconds.The total measurement (volume) of the acetate of collecting is 602 centimetres ³(be theoretical value 100%).

It is light grey and fibrous that the outward appearance of the polymkeric substance that makes is, and its logarithmic viscosity number is 1.4dlg ^-1Flow temperature is 290 ℃.The scope in anisotropy district be 290 ℃～more than 350 ℃.

2. matrix is injection-molded:

Polymkeric substance usefulness-Battenfeld BSKM 100/70S DS2, the processing of 000 injection machine.Adopt the disc type mould of surface finish, the feature of mould is that diameter is 95 ± 0.10 millimeters; Thickness is 2 ± 0.025 millimeters; The diameter of central authorities' geat is 4 millimeters.

Condition of moulding is as follows:

Mold surface temperature: 130 ℃,

Polymer-melt temperature: 320 ℃

Inject time: 2.5 seconds,

Injection pressure: 120 MPas,

Keep-up pressure: 90 MPas.

3. the machining of matrix:

After the demoulding and the cooling, in matrix, process a diameter and be 25 millimeters coaxial center pit.

4. the performance of the matrix of molding;

A. surface quality

Surfaceness: 0.02 micron;

False sinusoidal planarity defects: 50 microns of cycles; Amplitude: 2～4 microns.

(these characteristics are that the condition during mensuration is: adopt quiet feeler, its end radius is 0.013 millimeter, and the motion of the vertical direction of sensor is amplified with electronics with the Taylor-Hobson Instrument measuring of Talystep by name; The sensor contact load is 50 milligrams; Signal interruption frequency: 0.76 millimeter; Sensitivity: 20 dusts.〕

Contraction during the demoulding: do not have

B. mechanical property

Mechanical property is to use from radially (flow direction) and the horizontal sample of getting of the matrix of molding gained to measure:

Tensile property:

Intensity and elastic modulus are the regulations according to French Standard NFT51034, and 50% relative humidity is measured through the dumbbell-shaped specimen to 4 mm wides, 2 millimeters thick of status adjustment under 23 ℃, and the relative humidity when regulation is measured is 50%.Measurement result is:

Radial elastic modulus (Mr): 12,700 MPas,

Transverse modulus of elasticity (Mt): 6,600 MPas,

Radial drawing intensity: 100 MPas,

Elongation during fracture: 3%.

Thermal expansivity:

The dimensional stability of matrix is to be that the coefficient of linear thermal expansion of 5 * 5 * 2 millimeters parallelepipedon sample is evaluated by size up, records radial line expansion coefficient (α r) under-30 ℃～+ 30 ℃ temperature and the drying nitrogen and x wire thermal expansivity (α t) is according to being defined in of ASTM standard D696-70:

α r:14 micron/rice/℃,

α t:180 micron/rice/℃.

DTUL：

Deformation temperature under the load is to measure according to the regulation of French Standard NFTT51005; DTUL under 1.82 MPa loads is 250 ℃.

C. physical and chemical performance:

Relative density: d=1.45.

Crystallinity: structure is a miocrystalline.

Solvent resistance: fabulous; For the evaluation solvent resistance, according to French Standard NFT51034 7 samples are immersed in the solvent, be heated to the temperature of regulation and keep official hour, measure the average radial pulling strengrth of these 7 samples then.Though if pulling strengrth has and descends but still at original more than 90% of value, just can think that its solvent resistance is fabulous.

Solvent and test condition pulling strengrth: the original percentage of intensity

Triclene; 50 ℃ following 7 days 100%

37%H ₂SO ₄; 50 ℃ following 7 days 90%

20%H ₂SO ₄; 50 ℃ following 30 days 100%

20%HCl; 50 ℃ following 30 days 97%

Water absorbing capacity: be lower than 100ppm; Assay method is as follows: according to French Standard that sample is following dry 3 hours at 150 ℃, weigh (Wo), in 23 ℃ of water, soaked 48 hours then, after the time, sample is taken out from water, its surface is dried, and (W) again weighs: water absorbing capacity equals (W-Wo)/Wo * 10 ⁶

5. anisotropy

The in-plane anisotropy of mechanical property: i.e. Mr/Mt, this ratio equals 112,700/6,600=1.92

The anisotropy of depth direction: i.e. α r/ α t, this ratio equals 14/180=0.07.

Embodiment 2

Prepare the example that contains the disk of magnetic paint base magnetic coat of the present invention.

1. the preparation of magnetic coating compound:

The method of preparation is that the trade mark that will can buy from Pfizer company on the market is that the acicular iron oxide that oozes cobalt of MO2228 (is rectified neck magnetic: 320 oersteds) be dispersed in and contain diethylene glycol dimethyl ether and 1,2-ethylene alcoholic solvent, epoxy resin-based adhesive system (can buy from Shell company on the market, its trade mark is Epikote1001), in the potpourri of polyvinyl acetal (can buy from Monsanto company on the market, its trade mark is BntvarP74) and N-aminopiperazine rigidizer.Solids content in the dispersion liquid (pigment+binder system) is a 30%(weight) magnetic paint account for deposition dry magnetosphere weight 55%.

2. coating deposits:

Then above-mentioned magnetic coating compound is overlayed on general centrifugal cladding process on the matrix of 95 mm dias of embodiment 1 gained, matrix carries out centrifugal coating with about 300 rev/mins rotating speed rotation in the time of 1200 rev/mins in the method.

The matrix that applied is handled with solvent evaporated, heated 4 hours down so that bonding agent is crosslinked at 190 ℃ then.The thickness of the magnetosphere of deposition is 0.60 micron.

The disk of gained only need polish on the felt dish with alumina fluid dispersion before being used to read a pen recorder slightly.Should be pointed out that disk also sprays a kind of lubricant before use, this lubricant is by containing 1%(weight) the Freon113 solution composition of perfluoroethylene ether (commodity that Montefluos company sells, trade mark is Fomblin Z).

The key property of the disk that makes like this is as follows: surfaceness is less than 0.025 micron; In reading a pen recorder, be easy to tolerate rising more than 10,000/end week; Electrical property is consistent with the value of requirement.

Claims (5)

1, as the smooth thin disc-shaped rigid polymer matrix of recording disc, it is characterized in that:

This polymeric material belongs to thermic and becomes polymer class, and its flowing temperature range is 200-350 ℃; Its logarithmic viscosity number is at least 1dlg ^-1, this logarithmic viscosity number is to use 100cm under 25 ℃ ³50/50 (volume) parachlorphenol/1, contain in the 2-ethylene dichloride flux potpourri that the solution of 0.5g polymkeric substance records; This polymkeric substance is selected from full-aromatic polyester, the alkyl aromatic polyester, and full aromatics poly-(esteramides), alkyl aromatic gathers (esteramides), poly aromatic azomethine, aromatic carbonate polyester and these mixture of polymers; This matrix method for making is thermic to be become polymkeric substance be equipped with in the mould that is applicable to polymeric material of central injecting systems one and carry out injection moulding, model temperature is 100-200 ℃, being subjected to the molten temperature of touching polymkeric substance of injection moulding is 280-350 ℃, be 2-10 second inject time, injection pressure is the 80-160 MPa, and keep-uping pressure after the injection is the 40-120 MPa;

The relative density of the matrix of molding gained is less than 1.8, and radial elastic modulus is the 9000-18000 MPa, and the radial thermal expansion coefficient is 10-20 micron/rice ℃, the deformation temperature under the load be 150 ℃ to melting point polymer.

2, matrix according to claim 1 is characterized in that its key dimension is: external diameter 70-360 millimeter, thickness 1-2 millimeter.

3, matrix according to claim 1 and 2 is characterized in that used thermic becomes polymkeric substance and is full-aromatic polyester, alkyl aromatic polyester, aromatic carbonate polyester and these mixture of polymers.

4,, it is characterized in that the logarithmic viscosity number of thermic change polymkeric substance is 1-4.0dlg according to any one described matrix among the claim 1-3 ^-1

5, comprise the sliding disc-shaped rigid polymer matrix of glimmer and be deposited on granular pattern or the magnetospheric recording disc of thin layer type at least one face of this matrix, it is characterized in that the feature of this matrix is as follows:

The polymeric material that is used for making matrix is that at least a thermic becomes polymkeric substance, and its flowing temperature range is 200-350 ℃; Its logarithmic viscosity number is at least 1dlg ^-1This logarithmic viscosity number is to use 100cm under 25 ℃ ³The 50/50(volume) parachlorphenol/1, contain in the 2-ethylene dichloride solvent mixture that the solution of 0.5g polymkeric substance records: this polymkeric substance is selected from full-aromatic polyester, the alkyl aromatic polyester, full aromatics poly-(esteramides), alkyl aromatic gathers (esteramides), poly aromatic azomethine, aromatic carbonate polyester and these mixture of polymers;

This matrix method for making is thermic to be become polymkeric substance be equipped with in the mould that is applicable to polymeric material of central injecting systems one and carry out injection moulding, model temperature is 100-200 ℃, the temperature that is subjected to the molten polymer of injection moulding is 280-350 ℃, be 2-10 second inject time, injection pressure is the 80-160 MPa, and keep-uping pressure after the injection is the 40-120 MPa;

The relative density of the matrix of molding gained is less than 1.8, and radial elastic modulus is the 9000-18000 MPa, and the radial thermal expansion coefficient is 10-20 micron/rice ℃, the deformation temperature under the load be 150 ℃ to melting point polymer.